1. Field of the Invention
The present invention relates to a method and apparatus for measuring the volume of toner consumed in a printer and, more particularly, to a method and apparatus for measuring the volume of toner consumed in a printer adopting a video data modulation technique.
This application is based on Korean Patent Application No. 2001-835, filed Jan. 6, 2001, which is incorporated herein by reference in its entirety.
2. Description of the Related Art
As shown in FIG. 1, a printer 102 is typically connected to a computer 101 via a communications interface 103. The computer 101 transmits data made by a user to the printer 102 via the interface 103, and the printer 102 internally processes received data and prints the processed data. Here, reference numeral 101a denotes an application program, reference numeral 101b denotes a printer driving program, reference numeral 102a denotes a printer controller board, reference numeral 102b denotes a printer engine, and reference numeral 102c denotes a manipulation panel.
In the prior art, a printer as described above adopts a sensor (not shown) to measure the volume of toner consumed. However, this printer is required to take remedial measures due to a lack of reliability and accuracy of the sensor that cause the malfunction of the sensor and/or difficulties with the use of the sensor. Consequently, a technique for counting a number of printing data that synchronizes with a video clock and for informing the system of a state of xe2x80x9ctoner exhaustionxe2x80x9d when the counted value reaches a predetermined reference value has been developed.
FIG. 2 is a block diagram schematically illustrating the structure of a conventional apparatus for measuring the volume of toner consumed, which adopts the aforementioned technique. Referring to FIG. 2, a conventional data required amount calculating apparatus 200 is made up of a count effective signal generation unit 201, a counting unit 202 and a total counted value and reference value storage unit 203. The count effective signal generation unit 201 receives video printing data and a video clock signal VCLK for synchronizing the print data from the computer 101 and generates an effective signal. Here, the video printing data and the video clock signal VCLK are generated by the printer controller board 102a. The counting unit 202 counts the number of pulses of a generated effective signal and calculates the number of video printing data actually required to print one page. The storage unit 203 accumulates counted values.
When a printer adopting the conventional data required amount calculating apparatus 200 having such a structure prints a pixel, the effective signal generation unit 201 generates an effective signal in which printing data keeping a value of 1 exists within a video clock. Then, the counting unit 202 counts the number of pulses of an effective signal generated while one page is being printed. Finally, the printer controller board 102a compares the accumulated value with a reference value and measures the volume of toner consumed.
In this conventional method of measuring the volume of toner consumed, the count effective signal generation unit 201, which is an AND gate, combines the bits of printing data. Thus, this conventional method is suitable for printers in which printing data is capable of expressing only two values, 0 and 1, and is allocated for a pixel that can be a barometer of the resolution, and then printed. However, in the event that the number of bits of received printing data changes to 8 bits, 4 bits and 2 bits in order to improve the quality of image, in particular, in the event of beam modulation (video data modulation) printers, this conventional method cannot accurately calculate the printing data that is actually required, and, consequently, cannot accurately measure the volume of toner consumed.
To solve the above problems, an objective of the present invention is to provide a method of measuring the volume of toner consumed, by which the volume of toner consumed can be accurately measured by calculating the exact volume of printing data actually required even when a multiple printing data value is allocated to one pixel, as in beam modulation printers.
Another objective of the present invention is to provide an apparatus for measuring the volume of toner consumed, which adopts the particular toner consumed volume measuring method in use by the printer.
To achieve the first objective, the present invention provides a method of measuring the volume of toner consumed in a printer, the method including the steps of: (a) converting printing data, which is input in units of multiple bits per pixel in synchronization with a video clock signal, into bit values corresponding to equal levels into which each pixel is divided depending on the number of bits; (b) generating a carry value by summing the bit values corresponding to the levels of printing data converted in step (a) with the previous bit value; (c) counting the carry value generated in step (b); and (d) multiplying the counted value obtained in step (c) by a predetermined value and measuring the volume of toner consumed using the resulting product.
To achieve the second objective, the present invention provides an apparatus for measuring the volume of toner consumed in a printer, the apparatus including: a buffer control unit for converting printing data, which is input in units of multiple bits per pixel, in synchronization with a video clock signal, into bit values corresponding to equal sections into which each pixel is divided depending on the number of bits; a summing register for generating a carry value by summing the bit values corresponding to the sections of printing data converted by the buffer control unit and a pre-stored bit value; a counting unit for counting the carry value generated by the summing register, thus generating a counted value; a multiplier for multiplying the counted value obtained by the counting unit by a predetermined number, thus obtaining a counted value product; a counted value storage unit for storing the counted value product; and a microcomputer for setting the counted value product to be a value for measuring the volume of toner consumed.